#include "drv_adc.h"
#include "drv_usart.h"


uint16_t adc_buf[100]={0};
void drv_adc_init(void)
{
	GPIO_InitTypeDef GPIO_InitStruct;
	ADC_CommonInitTypeDef ADC_CommonInitStruct;
	ADC_InitTypeDef ADC_InitStruct;
	DMA_InitTypeDef DMA_InitStruct;

	RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB|RCC_AHB1Periph_DMA2, ENABLE);
	RCC_APB2PeriphClockCmd(RCC_APB2Periph_ADC1, ENABLE);

	GPIO_InitStruct.GPIO_Mode=GPIO_Mode_AN;//模拟输入
	GPIO_InitStruct.GPIO_Pin=GPIO_Pin_1;
	GPIO_InitStruct.GPIO_PuPd=GPIO_PuPd_NOPULL;//浮空 不干扰数据采集
	GPIO_Init(GPIOB,&GPIO_InitStruct);

	ADC_CommonInitStruct.ADC_DMAAccessMode=ADC_DMAAccessMode_Disabled;//不使用DMA直接寄存器访问
	ADC_CommonInitStruct.ADC_Mode=ADC_Mode_Independent;
	// APB2 Prescaler  2分频     system_stm32f4xx.c中    ADCCLK最高频率36MHz，不能超过36       因此最低要四分频 84/2=21  
	ADC_CommonInitStruct.ADC_Prescaler=ADC_Prescaler_Div4;
	ADC_CommonInitStruct.ADC_TwoSamplingDelay=ADC_TwoSamplingDelay_5Cycles;//采样周期5个周期
	ADC_CommonInit(&ADC_CommonInitStruct);//ADC公共部分的配置
	
	ADC_InitStruct.ADC_ContinuousConvMode=ENABLE;//使能继续转换
	ADC_InitStruct.ADC_DataAlign=ADC_DataAlign_Right;//数据右对齐
	ADC_InitStruct.ADC_ExternalTrigConv=ADC_ExternalTrigConvEdge_None;//不使用外部触发
	ADC_InitStruct.ADC_NbrOfConversion=1;//通道数
	ADC_InitStruct.ADC_Resolution=ADC_Resolution_12b;//12位分辨率
	ADC_InitStruct.ADC_ScanConvMode=DISABLE;//扫描模式不扫描 通道数少于2个
	ADC_Init(ADC1, &ADC_InitStruct);

	DMA_InitStruct.DMA_BufferSize=100;//需要搬运数据的数量
	DMA_InitStruct.DMA_Channel=DMA_Channel_0;//DMA通道
	DMA_InitStruct.DMA_DIR=DMA_DIR_PeripheralToMemory;//外设到内存
	DMA_InitStruct.DMA_FIFOMode=DMA_FIFOMode_Disable;
	DMA_InitStruct.DMA_Memory0BaseAddr=(uint32_t)adc_buf;//目标地址
	DMA_InitStruct.DMA_MemoryBurst=DMA_MemoryBurst_Single;//单次突发
	DMA_InitStruct.DMA_MemoryDataSize=DMA_MemoryDataSize_HalfWord;//半字传输
	DMA_InitStruct.DMA_MemoryInc=DMA_MemoryInc_Enable;//是否自增
	DMA_InitStruct.DMA_Mode=DMA_Mode_Circular;
	
	DMA_InitStruct.DMA_PeripheralBaseAddr=(uint32_t)&ADC1->DR;//数据源地址
	DMA_InitStruct.DMA_PeripheralBurst=DMA_PeripheralBurst_Single;
	DMA_InitStruct.DMA_PeripheralDataSize=DMA_PeripheralDataSize_HalfWord;
	DMA_InitStruct.DMA_PeripheralInc=DMA_PeripheralInc_Disable;//外设地址不自增
	DMA_InitStruct.DMA_Priority=DMA_Priority_VeryHigh;
	DMA_Init(DMA2_Stream0, &DMA_InitStruct);

	ADC_RegularChannelConfig(ADC1, ADC_Channel_9, 1, ADC_SampleTime_84Cycles);//数据手册PB1---ADC12_IN9 采集顺序为1 数据采集时间84(采集时间越长越精准)
	ADC_DMARequestAfterLastTransferCmd(ADC1, ENABLE);//设置DMA触发条件
	ADC_DMACmd(ADC1,ENABLE);//使能ADC DMA
	DMA_Cmd(DMA2_Stream0, ENABLE);
	ADC_Cmd(ADC1, ENABLE);
	ADC_SoftwareStartConv(ADC1);//软件触发ADC，开始转换
	
}
uint16_t drv_adc1_avg(void)
{
	uint8_t i=0;
	uint32_t sum=0;
	for(i=0;i<100;i++)
	{
		sum=sum+adc_buf[i];
	}
	printf("sum=%d\r\n",sum);
	return (uint16_t)(sum/100);
}
